This is my Pimoroni Tufty 2040 Case with space for battery 2000 mAh. See below links and parts used.

You print only the back (I recommend you to print the front for better protection.

Do NOT overtighten the screws or you may damage the LCD.

Parts used:

1x - https://shop.pimoroni.com/products/tufty-2040
4x - M2x3mmx3.5mm thread brass inserts.
4x - M2x6mm screws
1x - Lithium Polymer Battery 3.7V 2000mAh (56mmx34.5mmx10.6mm): https://www.amazon.com/gp/product/B08214DJLJ/